| LCMS | LC-MS/MS |
| Full Name: Liquid Chromatography coupled with Mass Spectrometry | Full Name: Liquid Chromatography coupled with tandem Mass Spectrometry (MS/MS) |
| Quadrupole: Single quadrupole system | Quadrupole: Triple quadrupole system |
| Scan Mode: Only SIM Q1 scan mode or selected/Single Ion Monitoring (SIM) | Scan Mode: Both SIM and MRM -Q1 scan mode or selected/Single Ion Monitoring (SIM) and -Q1 scan and Q3 scan mode with Q2 fragmentation – Multiple Reaction Monitoring (MRM) |
| Identification: Q1 selects a parent /precursor ion ((M+H)+ or (M+H)– Ion) | Identification: Q1 selects a parent /precursor ion ((M+H)+ or (M+H)– Ion) Q2 fragments the above selected ion Q3 monitors the daughter/ product ion |
| Daughter/Product ions– Sometimes daughter/ product ions are monitored but cannot specifically confirm that these daughter ions are formed from a particular parent ion | Daughter/Product ions- Daughter/product ions are monitored and specifically confirm that these daughter ions are formed from a particular parent ion |
| LCMS identifies unknown compounds based on (Q1) parent/precursor ion only. | LC-MS/MS identifies unknown compounds based on (Q1) parent/precursor ion and (Q3) Daughter/product ion (Q1/Q3) |
| LCMS is less specific and sensitive when compared to LCMS/MS. Two or more compounds can have the same Precursor (Q1 ions) in a mixed sample. | LC-MS/MS is highly specific and sensitive when compared to LCMS. No two compounds can have the same daughter ions (Q3 ions) even though they have the same Precursor (Q1 ions). |
HPLC Troubleshooting – Problems with Chromatography
HPLC Troubleshooting – Problems with Chromatography
kshetra
July 26, 2024